Why does gravity bend light if photons have no mass?

[GijXiXj]

Fair point.

If you want to measure its invariant mass, there are lots of ways particle physicists do that too

Fair point. I guess they can just count the particles; or in a different situation the two alien space beings can just count the atoms in their lumps of "mass" of the same composition. And I'm sure they'd agree that those numbers had significance. Silly me.

Your other point, well, I guess "what really happens", ie: the result of experiment is the only test we have.

 

[trex1950]

The key to the why the photon can travel and be bent by gravity has nothing to do with it's mass. Because a photon has no mass. The answer is related to curvature to space-time due to light moving around an massive object. It is just following the curvature of space-time produced by the mass of a planet or star. It does not have any force, pressure, or gravity.

 

[Nano-Passion]

The key to the why the photon can travel and be bent by gravity has nothing to do with it's mass. Because a photon has no mass. The answer is related to curvature to space-time due to light moving around an massive object. It is just following the curvature of space-time produced by the mass of a planet or star. It does not have any force, pressure, or gravity.

You just bumped a 5 year old thread.

Doesn't photon get bent through space due to the electrical forces acted upon it?

 

[kirtg]

doesn't the kinetic energy of a photon give it a "mass" if energy=mass and mass=energy?

 

[kirtg]

if a photon is massless like the neutrino and has not charge like the neutrino, why doesn't it penetrate matter like the neutrino?

 

[Spourk]

if a photon is massless like the neutrino and has not charge like the neutrino, why doesn't it penetrate matter like the neutrino?

Neutrinos have mass.

 

[kirtg]

So if a nearly massless neutrino with no charge can penetrate matter with little likelihood of a collision, why doesn't a photon do the same thing"

 

[Matterwave]

The photon interacts with charged particles (like the electrons in atoms) via QED (EM forces basically). Neutrinos only interact with particles via the weak force.

Photons do not have rest mass.

In general, it's better to read the faq if you have some basic misunderstandings. If you can't find the answer in the faq or a quick search, then post a new thread, don't bump a ~decade old thread (holy crap PF is ~decade old!?).